1. Field of the Invention
The present invention relates to display devices, and more particularly to a technique that is effectively applied to an oscillator circuit that is built in a display panel.
2. Description of the Related Art
In recent years, a downsized liquid crystal display panel having thin film transistors (hereinafter referred to as “pixel transistors”) as active elements of respective pixels has been widely employed as a display section of a mobile device such as a cellular phone.
As the liquid crystal display module, there has been known a liquid crystal display module having the semiconductor layer of the thin film transistors made of polysilicon (hereinafter referred to as “polysilicon liquid crystal display module”). In the polysilicon liquid crystal display module, driver circuits such as a horizontal driver circuit and a vertical driver circuit are integrated with a liquid crystal display panel.
The transistors that constitute the driver circuits are formed of thin film transistors each having a semiconductor layer made of polysilicon (hereinafter referred to as “polysilicon thin film transistor”) as with the pixel transistor, and the polysilicon thin film transistors are integrated with the pixel transistors.